I'm confused about the exact details here -- does he believe there is an auto plate tracker which shows the name the vehicle is registered to (him) which gets a false-positive on a secondary search for name? It would seem more reasonable to have a list of suspects/warrants, and then a list of their own vehicles, and just pop it up then. You'd also want to find cars the suspect was known to drive, since it's pretty common for a "criminal" to register his property in someone else's name to protect from seizure.
I think it would be more plausible that he was profiled for race/location/type of vehicle/etc., rather than his name, but maybe there are more specifics?
Yes, I just don't see how an automated license plate scanner would get confused by a similar name -- I assume those have access to DMV database, so it would pull up 5DES800 and see it's registered to Marcus Walters of 1 Crypto Way who has 5 open warrants for overthrowing the state; it wouldn't say "this is a car registered to Marcus Walter" which the officer would then confuse with the open warrant for Marcus WalterS.
I suppose it's possible the ALPS could be configured to just ID every single car, and the officer had in his mind (or using another system) the name of a specific suspect who he matched (erroneously) to the ALPS results of the victim here.
I think it would be more plausible that he was profiled for race/location/type of vehicle/etc., rather than his name, but maybe there are more specifics?